Apparatus and method for a distributed conference bridge

Abstract

An apparatus and a method for a distributed conference bridge having a plurality of interface modules, each with voice signal bridging capability, connected by a bus. The present invention reduces the voice signal bandwidth requirement for the bus and increases the reliability of the conference bridge compared to a centralized conference bridge. An embodiment with conference participants connected to a second bus reduces the bandwidth requirement between the buses compared to a centralized conference bridge with participants connected to an auxiliary chassis.

1 . A distributed conference bridge comprising: 
 a bus, having a plurality of ports, for providing a signal received at one of said plurality of ports to all other of said plurality of ports; and    a plurality of interface modules, each for connecting to said bus via one of said plurality of ports, each having: 
 a line interface for receiving a participant voice signal and for providing a net conference voice signal;  
 a bus interface for providing said participant voice signal to said bus and for receiving, from said bus other participant voice signals; and  
 a signal bridging mechanism for generating said net conference voice signal from said other participant voice signals.  
   
     
     
         2 . The distributed conference bridge of  claim 1 , said signal bridging mechanism comprising: 
 summing means for summing together said other participant voice signals and said participant voice signal to generate a total conference voice signal; and    subtracting means for subtracting from said total conference voice signal said participant voice signal to generate said net conference voice signal.    
     
     
         3 . The distributed conference bridge of  claim 1 , said signal bridging mechanism comprising summing means for summing together said other participant voice signals to generate said net conference voice signal.  
     
     
         4 . The distributed conference bridge of  claim 1 , wherein the bus and the plurality of interface modules are incorporated in a telephony switching matrix.  
     
     
         5 . The distributed conference bridge of  claim 2 , wherein: 
 the line interface further includes means for receiving a second participant voice signal and for providing a second net conference signal;    the bus interface further includes means for providing said second participant voice signal;    the summing means further includes means for summing together the second voice signal with said other participant voice signals and said participant voice signal to generate the total conference signal; and    subtracting means further includes means for subtracting from said total conference signal said second participant voice signal to generate said second net conference signal.    
     
     
         6 . The distributed conference bridge of  claim 3 , wherein: 
 the line interface further includes means for receiving a second participant voice signal and for providing a second net conference signal;    the bus interface further includes means for providing said second participant voice signal;    the summing means further includes: 
 means for summing together said second voice signal with said other participant voice signals to generate said net conference signal; and  
   means for summing together said participant voice signal with said other participant voice signals to generate said second net conference signal.    
     
     
         7 . The distributed conference bridge of  claim 1 , further comprising: 
 a second bus, according to said bus;    a second plurality of interface modules, according to said plurality of interface modules, each for connecting to said second bus via one of said plurality of ports;    a first and a second inter-bus interface module for connecting to said bus and said second bus respectively, each via one of said plurality of ports, each having: 
 a line interface for receiving a participant voice signal and for providing a local conference voice signal;  
 a bus interface for providing said participant voice signal to said bus and for receiving from said bus other participant voice signals; and  
 summing for summing together said other participant voice signals to generate said local conference voice signal;  
 whereby said first inter-bus interface module is adapted to providing said local conference voice signal to said second inter-bus interface module as said participant voice signal and said second inter-bus interface module is adapted to providing said local conference voice signal to said first inter-bus interface module as said participant voice signal.  
   
     
     
         8 . An interface nodule for use in a distributed conference bridge comprising a bus, having a plurality of ports, for providing a voice signal received at one of said plurality of ports to all other of said plurality of ports and a plurality of interface modules, according to said interface module and including said interface module, each for connecting to said bus via one of said plurality of ports, said interface module comprising: 
 a line interface for receiving a participant voice signal and for providing a net conference voice signal;    a bus interface for providing said participant voice signal to said bus and for receiving from said bus other participant voice signals; and    a signal bridging mechanism for generating said net conference voice signal from said other participant voice signals.    
     
     
         9 . The interface module of  claim 8 , the signal bridging mechanism comprising: 
 summing means for summing together said other participant voice signals and said participant voice signal to generate a total conference voice signal; and    subtracting means for subtracting from said total conference voice signal said participant voice signal to generate said net conference voice signal.    
     
     
         10 . The interface module of  claim 8 , the signal bridging mechanism comprising summing means for summing together said other participant voice signals to generate said net conference voice signal.  
     
     
         11 . A method for operation of a distributed conference bridge having a plurality of interface modules each receiving a voice signal from and providing a net conference signal to a participant from a plurality of conference call participants, for each of the interface modules the method comprising the steps of: 
 a) receiving the voice signal from the participant;    b) providing, the voice signal to each of the others of the plurality of interface modules;    c) receiving a plurality of voice signals provided in step b) by the others of the plurality of interface modules;    d) summing together the voice signal and the plurality of voice signals to generate a total voice signal;    e) subtracting the voice signal from the total voice signal to generate a net conference signal; and    f) providing the net conference signal to the participant.    
     
     
         12 . A computer program product for operation of a distributed conference bridge having a plurality of interface modules each receiving a voice signal from and providing a net conference signal to a participant from a plurality of conference call participants, the computer program product comprising: 
 computer readable program code devices for:    a) receiving, the voice signal from the participant;    b) providing the voice signal to each of the others of the plurality of interface modules;    c) receiving plurality of voice signals provided in step b) by the others of the plurality of interface modules;    d) summing together the voice signal and the plurality of voice signals to generate a total voice signal;    e) subtracting the voice signal from the total voice signal to generate a net conference signal; and    f) providing the net conference signal to the participant.    
     
     
         13 . A method for operation of a distributed conference bridge having a plurality of interface modules each receiving a voice signal from and providing a net conference signal to a participant from a plurality of conference call participants, for each of the interface modules the method comprising the steps of: 
 a) receiving the voice signal from the participant;    b) providing the voice signal to each of the others of the plurality of interface modules;    c) receiving a plurality of voice signals provided in step b) by the others of the plurality of interface modules;    d) summing together the plurality of voice signals to generate a net voice signal; and    e) providing the net conference signal to the participant.    
     
     
         14 . A computer program product for operation of a distributed conference bridge having a plurality of interface modules each receiving a voice signal from and providing a net conference signal to a participant from a plurality of conference call participants, the computer program product comprising: 
 computer readable program code devices for:    a) receiving the voice signal from the participant;    b) providing the voice signal to each of the others of the plurality of interface    c) receiving a plurality of voice signals provided in step b) by the others of the plurality of interface modules;    d) summing together the plurality of voice signals to generate a net voice signal; and    e) providing the net conference signal to the participant.